The present invention relates to a system of controlling a sliding member for a vehicle, which is used for a sliding roof in a sunroof apparatus, for example.
A sliding roof has been used for a vehicle, which is mounted for the purpose of controlling the temperature of its cabin or providing a feeling of freedom for its passengers. This sliding roof is usually driven by a motor, which allows not only its sliding movement between open and closed positions, but also its tilting movement by lifting its end portion at this closed position.
A technique for controlling a sliding roof is disclosed, which selects mechanically locked positions at its open position and tilted position as reference positions, where the sliding roof discontinues its movement as a result of mechanical contact to a periphery of opening. Related arts are disclosed in Japanese Published Patent Application 2001-180283.
The technique disclosed in JP2001-180283 has a drawback that a sliding roof creates colliding noise or a motor generates uncomfortable noise such as beat noise. The reason for this phenomenon lies in the fact that the technique employs a reference point defined at a mechanically locked position in order to count pulse, where a sliding roof mechanically contacts with the periphery of opening. It may be anticipated that a method, which controls a sliding roof so as to stop slightly short of an open position or tilted position where the sliding roof contacts with the periphery of opening, possibly avoids creation of the noise.
However, it may occur that an actual position of sliding roof deviates from a theoretical position defined in a control system in the form of pulse counts. If no correction is imposed on this type of deviation, an anomaly such as erroneous creation of a gap between the sliding roof and the periphery of opening may occur, resulting in rain leaking.
Accordingly, even if the method described above is introduced for improving the technique disclosed in the patent document, there still remains a problem to be solved that displacement of sliding roof needs to be reliably detected so as to implement appropriate control for the position of sliding roof.
Furthermore, it is necessary to provide a system of controlling a sliding roof which is able to distinguish one type of irregular discontinuation of movement of the sliding roof caused by an obstacle between the sliding roof and the periphery of opening from the other type caused by displacement of the sliding roof.